1. Field of the Invention
The present invention relates to a cordless telephone.
2. Description of the Related Art
As one of services made by a telephone company, there is a notification service of a calling telephone number, a so-called number display service (hereinafter referred to as a xe2x80x9cND servicexe2x80x9d). This is such that when an incoming call is effected, data of a telephone number of a calling party giving the incoming call are transmitted to the telephone of the incoming call destination.
Thus, if a telephone corresponding to the ND service is prepared, at the incoming call, it is possible to display the telephone number of the counter party giving the incoming call. Alternatively, if a data table including a telephone number and a counter party""s name is prepared, at the incoming call, the name of the counter party giving the incoming call can be known.
When the ND service is used, if the data of the counter party""s telephone number are stored in a memory, even if, for example, there is an incoming call while a person is away from home, when the person comes home, it is possible to know the occurrence of the incoming call and the counter party""s telephone number. In the case of a cordless telephone, if the counter party""s telephone number is displayed on not only a base unit but also a portable unit, it is not necessary to take the trouble to go to the place of the base unit to see the telephone number, which is convenient.
However, in the case of doing so, when the person comes home and sees the counter party""s telephone number, the subsequent processing becomes a problem. That is, if such a structure is adopted that when the displayed telephone number has been confirmed, only the telephone number displayed on the telephone (base unit or portable unit) used for the confirmation is erased, with respect to the other telephones, it is necessary to go to the places of the respective telephones to erase the display.
Alternatively, the system can be configured to erase the number display on all telephones in the system when the displayed telephone number is confirmed. In a system with such a configuration, however, the displays can not be erased until the person to whom the call was addressed notes the telephone number.
Thus, the case where only the telephone number displayed on the telephone that is used by the person to perform the confirmation operation is erased, as well as the case where the telephone number displayed on all of the telephones is erased, are both inconvenient.
An object of the present invention is to solve the foregoing problems.
Therefore, according to the present invention, a cordless telephone comprises:
a base unit and portable units each including a display element for displaying a telephone number of a calling party; and
control means for controlling the base unit and the portable units,
wherein the control means carries out following operations:
in a case where any of the base unit and the portable units did not respond to an incoming call, display states of the display element of the base unit and the display elements of the portable units are respectively set to a first display state;
in a case where the base unit responded to the incoming call, display states of the display element of the base unit and the display element of the portable unit which is set to a first mode among the portable units are respectively set to a second display state, and
a display state of the display element of the portable unit which is set to a second mode among the portable units is set to a third display state; and
in a case where the portable unit responded to the incoming call, display states of the display element of the base unit, the display element of the portable unit having responded to the incoming call among the portable units, and the display element of the portable unit which is set to the first mode among the portable units, are respectively set to the second display state, and
a display state of the display element of the portable unit which is set to the second mode among the portable units is set to the third display state.
Thus, in accordance with the modes to which the portable units are set, the display elements of the portable units are notified or not notified that an incoming call has occurred.